This is a teaching given by Lord Krishna to his disciple Uddhava. This forms a part of Srimad Bhagavata Purana. In the Uddhava Gita, Lord Krishna imparts self-knowledge and the sadhanas needed for attaining this knowledge. In these ongoing talks, the Uddhava Gita is being explained in detail.
The entire collection of Swamiji's talks is available at the Poornalayam website.